A number of routes for the production of polycarbonate resins are presently available, and some of these are employed commercially. Generally, the commercial processes involve the use of phosgene, but the avoidance of use of phosgene is desired, because of the toxicity of the material.
A particularly desirable route to such polycarbonate resins would involve the use of a diaryl or substituted diaryl carbonate. However, while a number of processes have been described for the production of such diaryl carbonates, none to the best of my knowledge have proven economically feasible. Frequently, such processes prove to be uneconomical because of the amount of catalyst required, the type of catalyst, reaction time and rates, or the inability to recycle the catalyst.